Fluid pressure pump



Nov. 15, 1938., R. H. CARR FLUID PRSSURE PUMP Filed Dec. 24, l1934 Rickard H @arr Patented Nov. 15, 1938 UNITE stars FLUID PRESSURE PUMP Richard H. Carr, Chicago, Ill., assignor to The Pure Oil Company, Chicago, Ill., a corporation of Ohio Application December 24, 1934, Serial No. 759,036

6 Claims.

This invention relates to fluid pressure pumps and more particularly to force feed lubricators for the purpose of supplying lubricating fluid under pressure to working parts of mechanical devices.

Present types of force feed lubricators now in commercial use have several disadvantages. Leakage usually occurs between the plunger and cylinder wall resulting in low volumetric ehiciency. One reason for such leakage is the large diameter of the cylinder bore relative to the length of the liquid seal formed between the plunger and cylinder wall. Another reason for leakage is the slow speed at which present type commercial lubricators operate during the delivery stroke. A still further contributing factor is the arrangement of the driving mechanism in such a manner as to produce side thrust with resultant wear between moving parts.

My invention is designed to overcome the disadvantages inherent in lubricators now available for commercial use. By utilizing a cylinder and piston of Very small diameter in conjunction with a short and rapid spring actuated plunger stroke and an extremely long liquid seal, I have succeeded in obtaining a high volumetric efhciency. Moreover by constructing the lubricator in such manner as to permit the plunger to float freely in the working cylinder with the total actuating force on the plunger exerted in a direction parallel to the direction of movement thereof, the wear occasioned by the sliding surfaces is reduced to a minimum.

In addition to embodying the foregoing novel features, my invention also is concerned with a force feed lubricator or pump which is capable of adjustment without interruption of operation, whereby smaller quantities of oil can be delivered with a greater degree of positiveness at regular intervals than has been possible heretofore. 'Ihis feature of my invention is highly advantageous in connection with lubrication of mechanisms requiring only a very small amount of lubricant.

One of the novel features of my invention resides in the mechanism by means of which a plunger is made to reciprocate in a cylinder bore whereby a measured charge of lubricant can be drawn into the cylinder and be rapidly discharged.

Another novel feature of the invention is the arrangement of the actuating mechanism and the plunger whereby the stroke of the plunger can i be varied without affecting the normal stroke of the actuating mechanism and without interrupting the operation of the lubricator.

Still another feature of the invention is. the combination of spring actuating means and dash pot arrangement whereby the deliveryl stroke 5 can take place rapidly at high pressure without undue shock to the device.

Further novelty will be apparent from the following description considered in conjunction with the accompanying drawing, of which l0 Fig. 1 is a plan View of the lubri'cator with the top of the reservoir removed.

Fig. 2 is a vertical cross sectional view of the lubricator which forms the subject matter for my invention. 15

Fig. 3 is a vertical front end view of a portion of the lubricator;

Fig. 4 is a perspective view of a discharge valve;

Fig. 5 is a plan View of the suction valve; and

Fig. 6 is a vertical view of the suction valve. 29

Referring to the drawing, the numeral I designates generally a reservoir which may be a metallic box having a heavy bottom 2 and a removable top 3 which may be fastened to the resery voir by means of screws 4. The lid or top 3 has 25 an opening 5 therein in order to permit communication between the atmosphere and the inside of the reservoir whereby to maintainatmospheric pressure on the surface of the oil contained in the reservoir and to serve as an inlet for oil fed to the reservoir.

Mounted Within the reservoir is the lubricating mechanism designated generally by the numeral 6. The mechanism B is rigidly mounted 9, onto a plate 8 extending almost the entire length of the reservoir I and the plate is in turn fastened to the bottom 2 by means of bolts I0. The front or head end I2 of the lubricating mechanism is fastened to the plate 8 by means of bolts 40 I4. An abutting member I6 is fastened to the plate 8 by means of bolts I8. The member I6 has a circular opening I9 of suiciently large diameter to permit a part of the lubricating mechanism to reciprocate freely therein. rThe 45 opening is of larger diameter than the diameter of the reciprocating member.

The head end I2 has a narrow vertical bore 20 which is counter-bored adjacent the ends thereof in order to receive suction valve 22 and discharge 50 valve 24. The suction valve seat 26 is adapted to be screwed into the lower enlarged portion of the Vvertical bore 20, and the valve 22 is adapted to seat snugly against the upper end thereof. The valve seat 26 has a narrow bore 28 prefer- 55 ably corresponding to the diameter of the bore 2e. The lower portion of the head end I2 between the bolts I4 is cut out at 29 so as to form a space between it and the plate 8 to allow free passage Vof lubricant from the reservoir into the bore 20.

The upper enlarged end ofthe bore 20 has a valve 24 mounted therein which is adapted to seat tightly against the upwardly diverging faces 3| formed at the point where the bore 2D widens. A Valve body and seat 32 is adapted to be screwed into the upper enlarged end of the bore 20. The lower portion of valve body 32 has a passage 34 corresponding in diameter tothe bore 20 and is counter-bored in the upper portion thereof to receive Valve 35. is adapted to fit snugly against the upper end of the passage 34. A second valve body and seat 35, corresponding to valve body and seat 32, is adapted to be screwed into the upper end thereof. Valve bodyand seat 36 is adapted to receive and seat valve 3l in precisely the same manner as valve 35. A valve retainer plug 44 having a passage 46 preferably corresponding to the passage 34 is adapted to be screwed .intothe upper endv of the valve body and seat 35.

The valves 22, 24, 35 and 3'! may be octagonally sided as shown in Figs. l to 6, so as to allow sufficient space for oil toflow between the valve body and the sides of the valves. The upper face 47 of the valve 22 is arcuate and the top of the valve has arcuate grooves 48 and 49 at right angles to each other in order to permit oil to pass the valve when it is raised during suction. 'Ihe arcuate grooves 48 and 49 are deepest where they meet the sides of the valve and shallowest in the middle. The bottom 50 is shaped like an inverted cone and is adapted to vfit snugly against the bevelled upper edge of the suction valve seat 26. The valves 24, 35 and 31 are identical with valve 22 with the exception that the upper faces thereof are flat instead of arcuate.

The head end I2 is adapted lto t snugly against the inner surfaceof front wall 54. A long cylindrical projection, to form pump cylinder -member 55, extends horizontally from the rear of head end |2 and a somewhat shorter annular extension forms dash pot member 56 which surrounds the front end of member 55 andis spaced therefrom. The head end I2 and members 55 and 56 are pre-ferably cast as a unitary structure from brass or other suitable metal or alloy. The outer surface of the member 55 and the inner surface of the annular extension 56 are machined to provide sliding surfaces for a sleeve to be subsequently described. A horizontal cylindrical bore of suitable diameter extends completely through the head end I2 and member 55 and the front end of the bore is closed by screw plug'58. The horizontal bore and bore 20 lie in the same Vertical plane.

A plunger 'l0 is slidably mounted in the horizontal bore and adapted to reciprocate therein. The plunger 1|) is provided with a shoulder 14 at a point a short distance behind the rear end of member 55. The rear end 'I6 of the plunger 'I0 is somewhat enlarged to receive a washer 'I8 which is held in place by means of nut which may be screwed or otherwise attached to thel end of the plunger.

A sleeve member 8| is adapted to slide on the machined surfaces provided by member 55and extension 56 and through. the opening I9 in the abutting member I6. The sleeve is provided with orifices 82 to permit access of lubricant to the The lower face of the valve 35 moving parts enclosed therein. At its front end the sleeve is provided with an annular piston 83 cast integrally therewith, which is adapted to be slidably mounted in the annular space between the member 55 and extension 56. Immediately behind the annular piston 83 the sleeve is provided with an annular shoulder 84. The rear end of the sleeve extends approximately to the washer i8. The inner surface of the sleeve is provided with an inwardly extending annular shoulder 88 immediately behind the shoulder 'I4 of the plunger lil. A heavy coil spring 9|! encircles the sleeve 8| and abuts against shoulder 84 at one end and the member I8 at the other. A lighter coil spring 92 encircles the rear end of the plunger 'I and abuts against the shoulder 88 at one end and the washer 'E8 at the other.

A spacer block 94 is fastened to the bottom 2 by means of bolt 96 between the rear wall 98 of the reservoir I and the rear end of plate 8. A detent adjusting screw |89 extends into the reservoir through the rear wall S8 and is mounted in a stufng box gland |02 vwhich in turn is fastened tothe rear wall 98 by means of screws |04. A stuffing box gland nut |65 is mounted on stuling box gland |92 outside the reservoir. The screw IEN! is mounted directly in line with plunger 18.

A short shaft |58 extends through side Wall |09 and is mounted in bearing I I8 which in turn is fastened to side wall I 89 outside'the reservoir I by means of screws III. The inner end of the shaft is designated by the dotted line I I2. A pawl lever I I3 is mounted on shaft |38 inside the reservoir and adjacent the side wall |09. The lever ||3 is keyed to shaft |98' and is adapted to oscillate integrally therewith. A ratchet wheel I I4 is mounted on shaft |08 immediately adjacent lever I I3 and is adapted to rotate independently of shaft H18. Driving pawl I I5 is rotatably mounted at the end of pawl lever II3 by means of screw IIS. The pawl is held against ratchet wheel ||4 by means of a spring not shown. Av

brake pawl I I7 is rotatably mounted on the inside of side wall |99 by means of screw IIB which in turn is screwed into support H5. The support IIS is fastened to the side wall |09 by means of screw |25. The pawl II'I is held against the ratchet wheel |I4 by means of a Vspring not shown. The pawls II5 and II 1 are adapted to engage the teeth |2I of the ratchet wheel I I4.

A second shaft |22 of greater diameter than shaft |58 is recessed concentrically at |23 to provide bearing surface for the inner end of shaft |08. The inner end |I2 of shaft |03 is inserted in the recess |23 and is adapted to rotate therein, independently of the shaft |22. The end |24 of shaft |22 extends to a point adjacent the side of ratchet wheel I I 4 and holds the wheel in place. 'I'he opposite end |25 of shaft |22 is adapted to rotate in bearing I 26 which is fastened to side wall |21 by means of screws |28. The ratchet wheel I|4 is keyed to the shaft |22 by means of key |29 and rotates integrally therewith. A cam |3 is keyed to shaft |22 at a point immediately above shoulder 84. The shaft I 22 is located above shoulder 84 and slightly forward thereof in order that the cam |35 may co-act therewith. The shaft |08 is adapted to be oscillated by any suitable driving mechanism. It will be apparent that other suitable actuating mechanism may be used in place of that shown and described herein and the specific actuating mechanism shown and described is by way of illustration only.

A sight feed indicator |32 for observing .the

quantity and rate of flow of lubricant delivered by the lubricator is attached to the discharge line |35 by means of a suitable coupling |36;

The operation-of the lubricator is as follows:

The shaft |08 is oscillat-ed by means of any suitable actuating mechanism. The -lever ||3 being keyed to the shaft |08 oscillates therewith and at each stroke the driving pawl rotates the ratchet wheel H4 a short distance in the direction indicated by the arrows in Fig. 2. 'Ihe brake pawl Ill acts as a ldetent to prevent the ratchet `wheel from rotating in the opposite direction. The operation of the ratchet wheel causes shaft |22 to slowly rotate and the rotation of the shaft |22 brings the cam |30 into contact with the shoulder 84, causing it tomove backward against the compression of the spring 90. The

rearward movement of the sleeve tends to com-v press spring 92 which in turn causes the plunger 'l0 to move backward. The backward movement of the plunger 10 draws lubricating oil from the reservoir through orice 28, past valve 22 into bore and then into the horizontal cylinder or bore formed in the member 55 in which the plunger 'I0 reciprocates. The entire stroke or distance through which the sleeve 8| and the plunger 10 reciprocate may be approximately l inch. At the same time that lubricant is drawn into the cylinder, lubricant is also drawn through orice 66 into the annular space formed between the member 55, extension 56 and annular piston 83. This space forms a dash pot. As the cam continues to rotate it moves past the top of the shoulder 84 suddenly releasing it. The coil spring 90 drives the sleeve forward and the shoulder 88 of the sleeve pushing against the shoulder 14 of the plunger drives the plunger forward along with the sleeve. The lubricant in the annular space or dash pot between the member 55 and extension 56 is forced out through the small orifice 66 and takes up the shock of the forward movement of the sleeve. The diameter of the orifice 65 is small enough to olfer sufficient resistance to the discharge of oil from the dash pot so that the oil has a cushioning effect. It is evident that a valve controlled passage may be used instead.

The lubricant contained in the horizontal bore or cylinder is suddenly driven out through discharge valves 24, and 3l through discharge line |35 and sight indicator |32 to the desired points. The rapidity with which the lubricant is discharged minimizes leakage and enables a positive quantity of lubricant to be delivered at high pressures. The cam |30 continues on its journey around with the shaft |22 until it again meets the shoulder 84 and begins another suction stroke of the lubricator.

Due to the small bore in which plunger 10 reciprocates, the required compression of the spring 90 is relatively low. For example, with a bore of 3-2 of an inch, a coil spring having a compression of approximately 28 pounds at the beginning of the discharge stroke is sufficient to deliver oil-under a pressure of '750 pounds per square inch. The maximum compression of the spring 92 at the beginning of the discharge stroke may be approximately 10 pounds and should be sufficient to carry the plunger l0 the entire suction stroke traveled by the sleeve 8| when the plunger is not detented by the screw |00. Although I have found that a cylinder of approximately 4 inches in length and 315 of an inch diameter gives very satisfactory results with a plunger having a maximum stroke of 1/2 inch,

. on the suction stroke.

it will be understood that the length of the cylinder may be greater and the diameter of the bore and the compression of the spring 90 may be variedfto secure any desired delivery pressure.

In order to regulate the quantity of lubricant delivered bythe lubricator, the stroke of the plunger l0 may be varied by means of the detent adjusting screw |00. If it is desired to feed the maximum quantity per stroke that is possible, the screw is placed in such a position that it will not abut the rear end of the plunger l0 when the sleeve 8l is'at the end of the suction stroke. This permits the plunger 10 to travel toits full length stroke along with the sleeve. However, if it is desired to decrease the amount of lubricant delivered, the screw |00 is screwed inwardly until it will abut the rear end of the plunger 10 before the plunger reaches its most rearward position The stroke of the sleeve 8| continues as usual but the stroke of the plunger l0 is shortened and the difference in stroke is taken up by the coil spring 92. When the cam |30 releases the sleeve 8| the coil springs 90 and 92 drive the sleeve forward until the shoulder 88 thereof abuts the shoulder 14 of the plunger and the two then move forward in unison to discharge the lubricant.

It will be seen that I have devised a novelr means for force feed lubrication which is capable of flexible and long dependable operation due to its relatively simple structure and provision of means for eliminating to a great extent excessive wear on moving parts.

What I claim is:

l. A force feed lubricator comprising a cylinder, a plunger slidably mounted therein, a sleeve surrounding said cylinder, an annular cylinder in which said sleeve reciprocates, a passageway communicating with said first mentioned cylinder through which fluid can be drawn and discharged, a passageway communicating with said annular cylinder through which uid can be drawn and discharged, cam mechanism for actuating the sleeve during its suction stroke, a spring for actuating the sleeve during the discharge stroke, means for yieldingly actuating the plunger by means of the sleeve during the suction stroke and means for actuating the plunger by means of the sleeve during the discharge stroke.

2. A force feed lubricator comprising a cylinder, a plunger slidably mounted therein, a sleeve surrounding said cylinder, an annular cylinder in which said sleeve reciprocates, a passageway communicating with said first mentioned cylinder through which fluid can be drawn and discharged, a passageway communicating with said annular cylinder through which fluid can be drawn and discharged, cam mechanism for actuating the sleeve during its suction stroke, a spring for actuating the sleeve during the discharge stroke, an inwardly extending abutment on said sleeve and an outwardly extending abutment on said plunger immediately in front of said sleeve abutment and adapted to engage against it, a coil spring surrounding said plunger and abutting between said sleeve abutment and an abutment fastened adjacent the end of said plunger, and means for shortening the suction stroke of the plunger without affecting the stroke of the sleeve member.

3. A fluid pump comprising a cylinder, a plunger slidably mounted in the cylinder, a reciprocable sleeve mounted concentrically of said plunger and cylinder, said plunger being adapted to be freely spring actuated on the delivery stroke, and fluid cushioning means for reducing the shock of the delivery stroke of said sleeve comprising an annular cylinder in which the forward end of said sleeve is adapted to slide, said annular cylinder being closed at one end and having a restricted opening adjacent said closed end.

4. A force feed lubricator comprising a casing, a horizontally disposed pumping unit mounted on the bottom of said casing, said unit comprising an elongated cylinder, a plunger slidably mounted in said cylinder, a sleeve slidably mounted on the outer surface of said cylinder, a collar on said sleeve adjacent the forward end thereof, an annular cylinder having a restricted opening at one end and in which the forward end'of said sleeve is slidably mounted, an abutting member adjacent the rear end of said pumping unit, a coil spring surrounding said sleeve and abutting said collar and abutting member, a driving shaft, a cam on said shaft adapted to engage said collar inder, and driving means operable to reciprocate l0 said sleeve and said piston.

6. Means for cushioning the end of the forward stroke of aV spring actuated reciprocable sleeve member arranged rto actuate a pump plunger comprising an annular cylinder in which the forward end of said sleeve member iits snugly and is adapted to slide therein, said cylinderv being closed at one end and having a restricted opening adjacent said closed end.

RICHARD H. CARR. 

